Vertex Weight transfer in percentage, best way?

Hello, i got some successful method of transferring VertexWeight between bones in a single armature, but i find it still a bit too time consuming and not efitient as i think this process coud be.
Here’s some screenshots to simplify the explanation.

If not as a reference for my question maybe someone finds this helpful in some case XD

Im using Voxel Heat Diffuse Skinning so at the end its just tweaking weight betwen some bones.
Sometimes i just need to do those minor tweaks, but manually painting over is the worst solution for me…more time consuming and less precise :(.
Often i just add aditional bones and transfer there weights to the main bone with VertexWeightMix modifier or GYAZ Animation Tools - Rig Reducer.

The thing that i miss from max is the vertex exclude option. Lets say you got a necklace and you only need the neck and chest bones to influence it so you exclude other bones ;] not as simple in blender:(

Is there any other workflow or addons to speed up the process ?